The present invention relates generally to disposable absorbent garments and, more particularly, to a disposable absorbent garment having a stretchable ear portion and a method for making such a disposable absorbent garment.
Disposable absorbent garments contemplated by the invention include disposable diapers, disposable pull-on garments, and the like. These garments are worn about the lower torso or waist of the user so as to receive and contain urine and other bodily wastes. Disposable diapers are particularly intended for use on infants who depend on a caretaker to fit the diaper. Typically, the infant is laid down while the caretaker places the garment around the waist region of the infant and then secures two ends on each side of the diaper together.
Disposable pull-on garments include training pants, pull-on diapers, disposable underwear, and adult incontinence garments. It is generally expected that the user of any one of these garments will be able to put on and take off the garment on his her own. As for training pants, these garments are intended for use on a young child just before or about the time the child is ready to graduate from diapers to regular underpants (i.e., during toilet training). Training pants (and other disposable pull-on pants) have closed sides such that the user or care giver raises the garment about the user""s legs to put it on and slips the garment downward about the user""s legs to take it off. Thus, training pants (and other pull-on pants) are designed to be put on and taken off in the same manner by which regular underpants are put on and taken off. This feature is particularly advantageous in toilet training because it provides an early introduction to underpants and, more specifically, trains the child to wear regular underpants. Similarly, it is advantageous that the training pants fit and look very much like regular underpants so that the child is comfortable in making the transition from training pants to regular underpants.
The principal elements that typically makeup the disposable absorbent garments described above are a liquid-permeable inner layer, a liquid-impermeable outer layer and an absorbent core sandwiched between the inner and outer layers. Elastic members may also be incorporated into different parts of the garments. For example, elastic members may be positioned longitudinally along the diaper, generally outboard of the absorbent core to effect a seal around the buttocks, legs or both of the user. In addition, several elastic members (e.g., in the form of elongated elastic threads) may be positioned laterally throughout the waist region (including the side waist regions) of a disposable absorbent garment to allow the garment to stretch when it is put on and then during wear. In this way, the garment can stretch to accommodate variations in waist size and leg size of the user, while fitting snugly about the waist and legs and without sagging. One drawback, however, is that the elastic strands are visible on the outer surfaces of the garment and can interfere to some extent with decorative or instructional printing displayed on the outer surfaces of the garment.
It is also known to provide disposable garments with separate side waist regions in the form of elastic side panels such as those disclosed in U.S. Pat. No. 4,938,753. The elastic side panels described therein have side edges which are attached to the outer edges of a central absorbent core assembly. The elastic side panels may be made from various elastomeric materials or combinations thereof and provide a more uniform fit generally more snug than side waist regions having elongated elastic strands. Moreover, the elastic side panels provide outer surfaces which are more uniform than the outer surfaces on side waist regions having elongated elastic strands. However, the elastomeric material for the side panel does not typically provide for a smooth, even outer surface when the side panels are in either the relaxed state or the stretched state. Accordingly, the side panels are not particularly conducive to having decorative or instructional printing displayed thereon.
Alternatively, it is known to provide a unitary pair of training pants with elasticized ear flaps such as those disclosed in U.S. Pat. No. 5,246,433. The elasticized ear flaps are formed by sandwiching a relaxed elastomeric element between two material layers of the ear flaps, and adhesively attaching the material layers to the relaxed elastomeric element to form an elastic laminate. The design also calls for mechanically stretching the elastic laminate such that the material layers permanently deform. Although the side waist region according to this design generally provides a more uniform fit than a side waist region having elongated elastic strands, the outside surfaces of the side waist region are not conducive to having decorative or instructional print displayed thereon because the mechanically stretched material layers are uneven and cannot fully return to their original undistorted configuration.
It is, therefore, a principal object of the present invention to provide a disposable absorbent garment that is stretchable or extendible to fit snugly around the waist region of the user, is comfortable to wear and is conducive to having decorative or instructional printing displayed thereon. More particularly, the disposable absorbent garment should have side waist regions or ear regions that specifically include these attributes.
It is another feature and object of the invention to provide a disposable absorbent garment in the form of a training pant or an adult incontinence garment that fits and looks very much like regular underpants.
It is yet another feature and object of the present invention is to provide a disposable absorbent garment in the form of a diaper that has extendible or elasticated ear portions which provide adjustable and comfortable fit.
It is yet another feature and object of the invention to provide a disposable absorbent garment that can accommodate a wide range of user waist and leg sizes.
It is yet another feature and object of the invention to provide a disposable absorbent garment that is aesthetically pleasing.
It is yet another feature and object of the invention to provide a disposable absorbent garment that fits snugly and minimizes sagging.
It is yet another feature and object of the invention to provide a method of manufacturing a disposable absorbent garment that promotes efficiency and product quality.
Thus, in accordance with one aspect of the present invention, there is provided a disposable absorbent garment that includes a first material layer on the inside of the garment (or top sheet), a second material layer on the outside of the garment (or backsheet), and an absorbent core disposed between the inner sheet and the outer sheet. These components are assembled together to form a layered assembly or composite web structure having a front region, a back region, and a crotch region extending between the front region and the back region. The layered assembly is also characterized by a longitudinal plane that extends substantially centrally through each of the front region, back region, and crotch region. Further, each of the front and back regions includes at least a pair of ear portions which extend in substantially opposite lateral directions with respect to the longitudinal plane. At least one, but preferably all, of the ear portions includes a layered section including at least one, but preferably two (e.g., an ear inner layer and an ear outer layer), outer material layer and a stretchable member (e.g., an elastic film or heat-activated film) extendible between a contracted configuration and an extended configuration. The outer material layer is secured to the stretchable member when the stretchable member is disposed in an extended configuration such that the outer material layer is subsequently contractible then extendible with the stretchable member.
In another aspect of the invention, the stretchable member is secured to the outer material layer such that the outer material layer is extendible with the stretchable member from a contracted configuration to an extended configuration. In its extended configuration, the outer material layer provides an outside surface that is disposed in a substantially planar configuration.
In accordance with another aspect of the present invention, there is provided a method of making a stretchable or elasticated ear portion in a disposable absorbent garment or alternatively, in a composite web structure of the garment. Such a web structure may be subsequently folded, cut, trimmed, or otherwise treated to form a finished disposable absorbent garment ready for packaging or wear. This method includes the initial steps of providing the following: a first layer (e.g., a topsheet) having front and back longitudinal ends and a pair of opposing lateral edges; a second layer (e.g., a backsheet) having front and back longitudinal ends and a pair of opposing lateral edges; an absorbent core; and at least one stretchable member (e.g., an elastic member). The stretchable member is positioned adjacent a first section of the first layer, the first section being located proximate one of the lateral edges and one of the longitudinal ends of the first layer and the second layer (i.e., an ear region). This first section is then secured to the stretchable member such that the first section is subsequently extendible with the stretchable member.
Then, the first layer, the second layer and the absorbent core are secured or otherwise assembled together to form a web structure having a central longitudinal plane and including a front region, a back region and a crotch region. The front region includes the front longitudinal ends (of the first and second layers) and a pair of ear portions extending in substantially opposite lateral directions with respect to the longitudinal plane. Similarly, the back region includes the back longitudinal ends (of the first and second layers) and a pair of ear portions that extend in substantially opposite lateral directions with respect to the longitudinal plane. As a further result, the first section and the stretchable member are included in one of the ear portions to form a stretchable ear portion in the web structure.
The disposable absorbent garment according to the invention (including disposable diapers, training pants, adult incontinence garments and other pull-on garments) has a side waist region that displays a smooth, substantially planar outer surface when the garment is worn and the side waist region is stretched or extended. More particularly, the garment has an extendible or elasticated side waist region formed by joining a pair of extendible or elasticated ear portions which can extend from a wrinkled or slacked configuration to an extended condition wherein it displays a smooth, substantially planar outer surface. To form the ear portion, an inside surface of the outer and or inner layer of the ear portion is first extended (but not necessarily stretched) until it displays a smooth, substantially planar outer surface. Then, the inside surface of the layer is secured to a corresponding surface of a stretchable member (e.g., an elastic member) that is maintained in an extended configuration. When the stretchable member is allowed to contract, the secured layer contracts also and displays an outer surface characterized by wrinkles and a series of undulations (e.g., exhibits gathers). However, when the stretchable member is subsequently extended (e.g., when the garment is put on by the user), the secured layer extends with the stretchable member to smooth out its outside surface. The secured layer may be extended with the stretchable member to the extent the outside surface is returned to its initial substantially planar configuration.
The side waist regions of the invention advantageously allows for an improved snug fit, yet comfortable, waist fit that can adjust dynamically to the wearer""s waist expansion and contraction. Additionally, the side waist region""s smooth appearance when extended provides for the inclusion of decorative and or instructional printing on the outer surfaces of the ear portions which are legible (i.e., xe2x80x9cunbrokenxe2x80x9d), aesthetically pleasing and practical. Moreover, the side waist regions can combine with the front and back waist regions to provide a substantially continuous smooth surface all around the garment whereon decorative or instructional printing may be displayed.
It should again be noted that the invention is adaptable to various types of disposable absorbent garments including, but not limited to, disposable diapers, training pants, adult incontinence garments and other pull-on garments.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and the drawings.